U.S. Pat. No. 5,002,120 discloses an arrangement wherein a flexible hose is stored on a rotatable drum in a limited number of turns whereby the drum is rotated to extend the hose through a rigid laterally disposed and substantially straight guide or housing. The hose is connected to a plurality of separate or individual lances each having a length approximating the length of the rigid guide or housing such that when the hose is withdrawn onto the drum, the individual lances are substantially withdrawn into the guide or housing. The arrangement disclosed is intended to enable a plurality of lances to be moved through conduits or pipes to be cleaned simultaneously. The disadvantage with the disclosed system is that the exit point for the hose from the drum is fixed thereby substantially limiting the length of hose that might be stored on the drum and as a result limiting severely the possible length of movement of travel of each of the lances. Moreover a quite large length of head room is required in front of any bundle or array of tubes to be cleaned to enable positioning of the equipment if the tubes are to be cleaned in situ as would be desired in most circumstances. If this required head room is unavailable in any existing installation, then the tubes could not be cleaned with this equipment without removing same from the position in which they are installed.
Another arrangement is disclosed in Patent Cooperation Treaty Application No. PCT/AU90/00126 which discloses apparatus for projecting devices through tubes and conduits, said apparatus comprising a drum captured within a cage of axially disposed rollers and provided with a spiral groove on its outer surface, said drum being rotatable by drive means to extend from or retract back into said groove a cleaning lance, umbilical cable for a survey unit or the like, said drum being axially displaced during rotation to maintain the point at which said lance, umbilical cable or the like exits from or re-enters said groove in alignment with a tangentially arranged guide tube.
The aforesaid arrangement has worked satisfactorily but it has been found desirable to make some practical modifications to the system to improve its simplicity and portability. This arrangement involves both axially and rotationally moving the drum and flexible lance or umbilical cable or the like which requires considerably larger power units to drive the system and involves the use of more power in operation. Moreover, the system, because of this complication is larger and more complicated than might be otherwise needed.
The objective therefore of the present invention is to provide apparatus which is capable of projecting a stiffly flexible elongated member through a conduit, tube or the like which requires a minimum of space in front of the conduit, tube or the like being worked upon, but which is relatively simple in construction.